regular expression for numeric range in python

Use the python package regex_engine for generate regular expressions for numerical ranges

You can install this package by using pip

pip install regex-engine

from regex_engine import generator

generate = generator()

regex = generate.numerical_range(0,3000)

print(regex)

^([0-9]|[2-8][0-9]|1[0-9]|9[0-9]|[2-8][0-9][0-9]|1[1-9][0-9]|10[0-9]|9[0-8][0-9]|99[0-9]|[2-2][0-9][0-9][0-9]|1[1-9][0-9][0-9]|10[1-9][0-9]|100[0-9]|300[0-0])$

You can also generate regexes for floating point and negative ranges

from regex_engine import generator

generate = generator()

regex1 = generate.numerical_range(5,89)
regex2 = generate.numerical_range(81.78,250.23)
regex3 = generate.numerical_range(-65,12)

If you want to match ranges of integers, you need to protect the matches with r"\b" (begin/end of string):

>>> import re

>>> text = "2016, CLP2012 56-900 3000-3000 4000-4000 123-123 0-0"
>>> re.findall(r"\b\d+-\d+\b", text)
['56-900', '3000-3000', '4000-4000', '123-123', '0-0']

If you want to match only integers from 0 to 3000, you need a more precise RegEx, like this:

>>> r = r"(?:3000|[1-2]\d{3}|[1-9]\d{2}|[1-9]\d|\d)"
>>> re.findall(r"\b" + r + "-" + r + r"\b", text)
['56-900', '3000-3000', '123-123', '0-0']

This code extract just a true range x-y and x< y <= 3000

sentence = 'test 69 example 55-66 example 77-44 example 999-3001 example'

for word in re.findall('\d+-\d+', sentence):
    l = word.split('-')
    if int(l[0])< int(l[1]) <= 3000:
        word

Output for this example :

'55-66'

For a modern solution, head to my fork of regex-engine, range-ex

pip install range-ex

Pass a minimum and maximum value to the range_regex function to generate a regex that matches numbers in that range. The range is inclusive, meaning both the minimum and maximum values are included in the regex.

from range_ex import range_regex

regex1 = range_regex(5,89)
# ([5-9]|[2-7][0-9]|1[0-9]|8[0-9])

regex2 = range_regex(-65,12)
# (-[1-9]|-[2-5][0-9]|-1[0-9]|-6[0-5]|[0-9]|1[0-2])

Note: This will still find matches in strings like 1234 or abc25def53, so you may want to wrap it in ^ and $ to match the whole string or \b...\b to ensure word boundaries are matched.

If you only pass one of the two arguments, the other will be set to None, which means it will not be constrained. In this case, the regex will match any number that is greater than or equal to the minimum or less than or equal to the maximum.

regex3 = range_regex(minimum=5)
# (([5-9])|[1-9]\\d{1}\\d*)

regex4 = range_regex(maximum=89)
# (-[1-9]\\d*|([0-9]|[2-7][0-9]|1[0-9]|8[0-9]))

This package resolves a bug in regex-engine for negative ranges including 0 and adds the option for unbounded ranges (lower/upper bound only).